Below is a fun map and infographic from the folks at College Raptor.
3) About six in 10 senators went to college in-state.
(Note: The map includes only where senators obtained undergraduate degrees from. Two senators -- John Boozman of Arkansas and Rand Paul of Kentucky -- never completed their undergraduate degrees, but do have advanced degrees.)
* Potential bias involved
Corrections: College Raptor's map originally had Sen. Thom Tillis (R-N.C.) as a University of Maryland graduate, when he graduated from the University of Maryland University College. It also had one of Oregon's senators graduating from the University of California; both graduated from Stanford University. Finally, an errant Georgetown "G" was briefly placed over Sen. Mark Warner's (D-Va.) alma mater, George Washington University. These errors have been fixed in the above graphic.